Intrusive etl::tree_link rotate behaviour

[serges147]

Hello!

I'm building a new etl::intrusive_avl_tree class (AVL tree), and it seems natural (and consistent with other "intrusive" collections) to use already existing etl::tree_link type and its utilities (like etl::link_rotate etc.).

But I encountered problem with the "etl::link_rotate_left/right" functions - they update most of the links according to the desired rotation but for some reason one is missed - a child link at parent of leaf is not updated to point to the leaf. As a result, tree becomes broken after rotation (unless you write extra line to fix it afterwards).
See:

etl/include/etl/intrusive_links.h

Line 1316 in c600605

}

@jwellbelove John, here is the question: Is there a reason or some design idea why grandparent's link is not updated?

BTW, the described above issue could be easy reproduced at the test_tree_link_rotate_left test by adding one extra check line like: CHECK(r.etl_left == &a); after rotation.
See:

etl/test/test_intrusive_links.cpp

Line 1629 in c600605

Thank You!

[jwellbelove]

I'll take a look.

[jwellbelove]

Can you raise this as an issue?

[serges147]

Done - see issue #1297 .
So, it was not intended/designed like that, but more like an oversight, right? Thnx!

[serges147]

It was indeed a bug - fixed by issue #1297 .